I Can't Quit You
by TheWolfWithinMe
Summary: When Greg almost loses Sherlock to a drug overdose, he's forced to admit just how much he truly cares for the sociopath. With devastating consequences. [Sherstrade / JohnLock]
1. Chapter 1

A/N - Just a short first chapter to get me started.

Pairings: Sherstrade/JohnLock

Disclaimer: All I own is the plot idea. Nothing else.

Set during S1/S2.

* * *

/I need you, Greg - SH./

Lestrade's phone vibrated in his pocket, nudging him out of his daze. A pile of paperwork lay in front of him, the words getting smaller and smaller as the night dragged by. At this rate, he would be at Scotland Yard until the morning.

With a yawn and a hair ruffle, the DI slipped out his phone and swiped open the message. His tired eyes stared at the screen until the words sunk in, and then, without another wasted second, he was out of his office and halfway down the corridor.

His phone buzzed for a second time as he hurried through the lobby, his friends and colleagues giving him a raised brow as he rushed past them.

/Greg, have you seen Sherlock? He's not picking up his phone - John./

He was out of the doors now, his silver BMW only a few feet away, lights flashing as he quickly unlocked it. Pressing his phone to his ear, he called John, the rings lasting only a second before the other man picked up.

"Greg?"

Even with one word, one tiny word, Lestrade could hear the panic in the doctor's voice, and it did nothing to calm his own nerves.

"What happened?!" The phone was now pressed against his shoulder, his shaking fingers fumbling to get the key into the ignition. Damn, he needed a smoke.

"He... he got a text. Said he would be back, but that was hours ago." John broke off and Greg could hear another voice in the background, one that sounded vaguely familiar. "Mycroft's here too." The doctor continued a moment later, a little calmer now. "He's tracing Sherlock's phone as we speak."

Finally starting the car, Lestrade pulled out of the parking lot and headed towards Baker Street. His phone vibrated for the third time against his ear.

"I'll call you back, John. Keep me updated." He said hastily before checking the new text. It was from Sherlock again, but the words made his heart sink.

/I've fallen, Greg. - SH/

The last time Sherlock had said those words, he had relapsed and given into his drug addiction. But he was different now, wasn't he? He had John, and though Greg was originally jealous at being replaced, he was happy that the army doctor managed to keep Sherlock out of danger. But this text, and the fact that he had gotten the DI's name right twice in a row, worried him.

No, scrap that, it _terrified_ him.

Jerking the car down an empty road, Greg headed for the rougher side of London, the place where he had first met Sherlock. If he really did fall off the rails, he would be here.

The clock in his car rolled over to midnight just as he pulled into an empty parking lot, the skies opening up a second later and drenching everything in sight. Fat raindrops slid down his windscreen but the DI could still see - something - in the distance. Wrenching open the door, he stepped out into the downpour, his silvery grey hair soon getting plastered to his forehead.

"Sherlock?" He called, yanking his coat over his head and starting forwards. The figure paused and turned in his direction, but didn't respond.

With a frustrated sigh, though it was more panic than annoyance, Greg broke into a run, ignoring his phone as it buzzed for a fourth time.

The figure wasn't Sherlock, yet it -was- wearing his coat. The DI's eyes narrowed as the homeless man turned to run. Ignoring the danger of the guy maybe having a knife, and silently wishing he had brought his gun with him, Lestrade dived at the man, sending them both crashing to the soaked ground.

"Where did you get that coat?!" He grunted, using his strength to pin the other male beneath him.

"Get off me!" The man growled back, arms flailing around as he tried to free himself. "He was dead! It's mine now!"

Greg's heart sunk for a second time and he loosened his grip a little, numb to the pouring rain, which ran down the back of his neck like little ice cubes, and the half-assed punches the man was trying to land on his chest. Dead. How could Sherlock be _dead?_

He had only seen him yesterday, so what had gone so wrong? Anger soon replaced the numbness and he glared down at the other man, one hand moving to press against his throat.

"Where is he? Show me!"


	2. Chapter 2

Disclaimer: I own nothing.

Pairings: Sherstrade/JohnLock

* * *

Greg's hand tightened around the man's throat when he didn't immediately respond. The lack of oxygen clearly brought out his _reasonable_ side, that or he just didn't have the patience, nor energy to deal with an irate DI all night, and he raised one hand, motioning at Lestrade's deathlike grip.

Loosening his fingers only slightly, Greg raised a brow.

"I saw... a guy," the homeless man started, his voice slightly strained, "he went into the tunnels and collapsed."

"So you left him there and stole his coat?" Lestrade growled, barely able to keep the anger out of his voice. "How charitable of you."

"Why should I care about another addict? The streets are littered with them." The man snapped back, fresh raindrops falling onto his face.

Addict? So Sherlock _was_ using again. This night was slowly getting worse and worse.

"Take me to him."

* * *

The tunnels lay on London's south side. A vast network of viaducts and unused railway tracks made the perfect shelter for the homeless, or the addicted. Dark and camera free, whatever happened down in the dank hallways, often stayed there.

Greg had only been there once, years and years ago. An international - _mafia_ \- if you will, used the tunnels to stage a massive drugs operation, spanning across Europe but using London as its headquarters. The culprits were a bitch to track down, thanks to the many exits and entrances, but after two months of careful planning and several failed attempts, all of the members were captured.

Returning to this location again made Lestrade nervous. What would possess Sherlock to come here? And all alone, too.

The homeless man was a little way ahead of Greg, his feet scuffing against the cracked pavement. He kept his head down as they both entered one of the tunnels, though Lestrade could hear him muttering to himself.

"If this is a trap, you _will_ regret it." The DI called out, his voice echoing off the damp walls. Water seeped through the brickwork above his head, the constant dripping making him more paranoid than ever. Maybe he should have brought back up with him, or at least someone else sane.

After what seemed like forever, though in reality it was only half an hour, the tunnel opened up into a clearing. Two lights were fastened to the wall, the eerie orange glow casting dancing shadows around the room. Below one of these lights, and looking like nothing more than a heap of old clothes and rags, lay a man.

His black curly hair instantly gave him away and soon Greg was running over, quickly forgetting all about the homeless guy.

"Sherlock?!"

Dropping down beside the heap of clothes, Greg tried to digest the sight before him. Needles, all of them used, were scattered around Sherlock's feet. Kicking a few out of the way, the DI growled, reaching forwards and roughly pulling the young detective towards himself.

Sherlock's body felt like a block of ice against Lestrade's warm chest, but he didn't complain, or utter a single word. Greg wasn't entirely sure the other man was conscious, and it scared him more than anything.

"Sherlock!" He started again, desperate now. Peering down at the mass of black curls which lay nestled against his body, he firmly shook the other male. "Wake up!"

He knew his fear could be heard, knew that he wasn't handling the situation very well, but what else could he do? Being calm and collective was fine when he didn't _know_ the victim, but this was Sherlock and... oh god. What was he going to do?

"Greg!"

Two flashlight beams hit the wall in front of Lestrade and he turned slightly, squinting against the brightness to see who else had joined the party. Albeit, a depressing one.

The person calling his name was obviously John, and Greg watched as the man skidded to a stop beside him. Crouching down, the doctor took Sherlock's face into his hands and mumbled something under his breath.

"How did you find us so quickly?" The DI asked, keeping an unusually tight hold on the young detective. He caught John's expression as the latter noticed his odd behavior, but luckily the blond decided not to comment. For now.

"Mycroft." He replied instead, jerking his head at something behind him.

Lifting his gaze towards the other flashlight, Greg saw another man; smartly dressed and carrying an umbrella. He was about to say hi when the man spoke, his voice unbelievably smooth.

"Thank you for finding him, inspector, but we can take it from here."

Greg frowned, "I'm not leaving him." He said stubbornly.

Mycroft sighed, then took a step forwards. "I could make your life very difficult, if it came to it."

"I wonder what it's like to have a difficult life." Lestrade shot back, though he reluctantly loosened his grip on Sherlock's body.

"Girls. Please." John cut in, scowling at Mycroft as he opened his mouth again. "The arguments can wait. Right now, we need to get Sherlock to hospital."

"You're right." Greg said quietly, all fight and stubbornness leaving him as quickly as it arrived. "He needs help."

With more reluctance, he untangled himself from Sherlock and stood up again, noticing out the corner of his eye that Mycroft was still staring at him. "What?"

"Thank you, Gregory."

Lestrade blinked in surprise. "For what?"

"Looking after my brother."

Brother? Well, that sure did explain a lot. He, like Sherlock, had an air of arrogance about him. But unlike the younger detective, who Greg had a _small_ soft spot for, Mycroft did nothing for the DI.

"You're welcome, I guess." He shrugged, "but I plan to always be here when he falls."

With a nod towards John, Lestrade turned and slowly headed back towards the tunnel entrance. He didn't want to leave Sherlock. In fact, turning his back on the sociopath tore at his heartstrings, but he knew that John would look after him.

He _always_ did.

A sour expression settled onto his face as he walked, his hands stuffed deep into his trouser pockets. Something suddenly moved to his right, causing him to stop in his tracks and glance around suspiciously.

The homeless man from earlier crept out of the shadows, looking extra gleeful and still wearing Sherlock's coat. "Trouble in paradise?" He sang, clearly high as a kite. "Well, you _are_ a bit old and... past it compared to that blond dude."

"Oh fuck off." Lestrade growled, walking even faster now to escape the annoying bastard.

God, he _really_ needed a smoke.


End file.
